Originally Posted By: benjy
your results confirm the closer viscosity spread is more durable, + even though amsoil 20-40 is prolly a group III refined CRUDE "synthetic" its surely better than a semi-syn with unknown amounts of "synthetic" surely group III. 20-40 is a good choice except when its colder where it flows slowly + may not start before the battery dies which happened with amsoil 20-50 in my traded sportster, 10-40 cured that + a 15-40 may as well work
I now have about 4,300 miles on the Amsoil, and a 4-day trip to Maine under my belt. That trip involved two, 10-hr. days of highway driving at 65-75 mph and about 1 hr. and 45 minutes of stop & go traffic (thanks Danbury, CT) in very warm conditions--the Amsoil performed great in all conditions, including start-up temps (in Maine)in the 40s. Oil consumption through this OCI has been nil. So far, Amsoil seems to be working. Stay tuned!